Furnace grate



Patented June 9, i925.

UITE STTES than earsnr caries.

JOHN D. MARTIN, OF NEW STRAITSVILLE, OHIO.

FURNACE GRATE.

Application filed May 10,

tain-new and useful Improvements in FurnaceGrates, of which the following is a specification.

When burning coal which cokes considerably upon a grate with overlapping grate elements in a series of steps, the coal being delivered at the uppermost step, there isapt to be a coke formation at the uppermost steps which forms more or less of a persistent solid mass which will not work downward over the grate as it should while being consumed. This is particularly the case with a conical grate in which the coal is fed up through the center into the hottest part of the furnace. Such a coke formation is objectionable for three reasons: First, it'

is difiicult' for the draft to find its way through it and burn it up thus making the grate. as a whole less effective. Second, large fragments of coke break off from the mass, roll down over the top of the fuel, reach the edge of'the grate before they can be completely burnt, and pass into the ash so that there will be too much combustible in the ash. Third, such pieces mix with the ash around the edge of the furnace wall, and being there, make the furnace wall and the ash so hot and in such a fused condition that they stick together, thereby resulting in the formation of considerable clinker 0n the wall. I

The object of this invention is, in a grate having overlapping rate elements in.a series of steps, to provlde means for intermittently lifting and separating the uppermost of the grate elements, and thereby agitating the fuel bed so as to prevent the formation of large coke masses. A further object is to provide a unitary operating mechanism which will se arate a number of the grate elements at t e same time by lifting the uppermost grate element the greatest distance and the ones below by progressively lesser amounts. A further object is, in connection with a revolving conical grate, to provide an actuating mebha-nism for this agitation which is carried around with the grate and which is actuated bystationary' elements with which the actuating'mechanism comes in contact. Such a grate to which this invention is 1924. Serial n0'.'712,24s.

particularly adapted is shown in my application for furnace filed Nov. 12, 1923, Serial No. (574C376.

In the accompanying sheet of drawings which forms a part of this specification- Figure 1 is a plan of a conical grate which embodies this invention, the grate elements being broken away, and

Fig. 2 is a vertical section through the grate.

A frame ring 10 through arms 11, 11 supports a vertical fuel-conveyor tube 12 in which a helical conveyor 13 is operated to lift and discharge fuel. I connects through arms 15, 15 with a hub 1.6 which turns on the fuel-conveyor tube above and supported from the ash-ring are overlapping grate-elements in the form of grate-rings of progressively diminishing diameter and spaced apart so as to leave horizontal passages between them. These form a conical'grate. A chain 17 revolves a sprocket wheel 18 on the fuel-conveyortube, and this carries with .it the ash-ring and the conical grate.

Lifting elements consisting of vertical rods 19, 19 and triangular rocker pieces 20,

20 are carried by guides 21, 21 attached to the spokes of the sprocket wheel through 35 which the rods pass, and forks 22, 22 attached to the spokes of the sprocket wheel to which the triangular pieces are hinged. The triangular pieces are pinned to the lower ends of the vertical rods and as the W has a series of contacting parts for engaging and lifting the grate-rings. The contacting parts are so disposed that the uppermost grate-ring will be first engaged and be lifted away from the one underneath.

Then the second ring will be engaged and 199 the two rings will rise together away from the third ring. Then the. third ring will be engaged and lifted away from the fourth ring along with the previous rings. The

four lifting elements operate and lift at the 1055 same time and lift slowly but the triangular pieces drop off from the stationary arms and the lifting elements and grate-rings fall back quickly. It is not necessary to operate on all of the rings but only on those 119 near the top which support the fresh fuel. The fuel bed is thereby agitated'and coking An ash-ring 14$ 70 into a large mass, both by the raising up and separation of the grate-rings and by their sudden drop back into place, is prevented.

I claim-- 1. In a furnace, a conical grate consisting of a series of superimposed rings, means for revolving the grate, lifting elements carried with the revolving grate for separating the rings, and stationary elements which are engaged by the lifting elements.

2. In a furnace, a conical grate consisting of a serles of superimposed rings, means for revolving the grate, liftingelements carried with the revolving grate each of which has a series of contacting parts for engaging and lifting the rings by progressively increasing amounts toward the uppermost, and stationary elements which are engaged by the lifting elements.

JOHN MARTIN 

